Targa Fiero

Unsafe At Any Speed · Tue Apr 17, 2007 11:55 pm

I just thought I would create this thread as a general source of information regarding targa top Fieros. Basically, I'd like input from everything from bracing to latches and seals. I know a few Targa Fieros exsist and there are a few Niller threads. Any thoughts, ideas, or pictures?

Unsafe At Any Speed · Wed Apr 18, 2007 12:33 am

Obviously, additional cross bracing to the underside is a must. That said, what sources are available? Any ideas on dimensions for making our own? Materials?

befarrer · Post by **befarrer** » Wed Apr 18, 2007 1:44 am

The frame cross support would be the same as a Convertable Fiero. The only difference would be in the roof.

Dirty Sanchez · Post by **Dirty Sanchez** » Wed Apr 18, 2007 8:51 am

We had a short discussion about convertibles on my forum.
http://www.fierodotcom.com/viewtopic.php?p=10261#10261
You can see several pictures of convertibles there and I also posted a picture of what the frame support looks like. B&B Spyder was offering a targa top for Fieros at one time, but I have heard that they have been having quality issues lately.

Unsafe At Any Speed · Wed Apr 18, 2007 11:42 am

Thanks for the info and link. I realize that some sort of bracing similar to a convertable is neccesary. However, I have still heard of some issues with these cars. So, my main focus at this point is getting the most out of the bracing to keep the car stiff. Unlike some, I do plan to still drive my car (hard at times). That said, I've come across a few different designs for the undercar bracing.

This is a new product that was posted up on Old E:
http://www.fierocountry.us/xframe.html
Supposedly its 1 x 1 and 2 x 1 tubing that is 14 gauge steel. It weighs in at 36 lbs. ($545)

Then there's this simplier design from the eBay link in the fierodotcom thread:

Not sure on the dimensions of the tubing or the weight. ($315)

Here's the bracing from B&B that the Dirty Rat uses:
http://Old Europe.hostkansas.com/pffimages/MVC-18F.jpg
http://Old Europe.hostkansas.com/pffimages/MVC-24F.jpg
I don't think any dimensions are ever listed for that set-up. Also, I wouldn't trust B&B at this point from all the negative feedback.

Obviously, the center removable section seems a must. Also, none of those really seem that complex. Wouldn't it be fairly easy to weld up a similar frame yourself? That said, I don't really know structural properties that well, but wouldn't round tubing be better? Or am I wrong?

Thoughts on the basic underframe reinforcement issue? Any other ideas to further strengthen the car in preperation? Ideally, you wouldn't want to add tons of weight, but it needs to be solid. Would it be beneficial to also add some bracing inside the car? Not visible neccesarily, but under the carpet along the bottom of the door or cross bracing behind the dash or the seats.

Looking at this thread http://realfierotech.com/phpBB/viewtopic.php?t=4087 it seems like that would be a good route to go for added stiffness on a targa/convertible application.

Thoughts in general? Pros/cons of a targa? At this point, I'm pretty set on a targa and I'm not the typical cheap ass Fiero owner. Not that I have tons of money, but I like to do things right.

Maybe this should be in Tech.

edit: The Niller links didn't work.

p8ntman442 · Post by **p8ntman442** » Wed Apr 18, 2007 11:51 am

all your strength is in the top and bottom fibers of the beam, therefore round tubing is about as bad as you can get. I beams are the best strength-weight you could hope for, and then rectangular tubing, then square tubing etc. the sides of the square tubing do nothing for you except add weight, but for cost, I doubt you could get the proper size I beams. The removable center section is only a must if you need to replace your gas tank, pump, or do other work in there. Swap in a high performance pump, and then road test it for a few months, if you dont have a factory lemon pump, you could weld in the center and then sawsall it out if you ever had to switch the pump in the future.

Unsafe At Any Speed · Post by **Unsafe At Any Speed** » Wed Apr 18, 2007 2:06 pm

Okay, that makes sense about the tubing. I do plan on an engine swap in the future so I will definatly need to upgrade the pump.

Unsafe At Any Speed · Post by **Unsafe At Any Speed** » Wed Apr 18, 2007 9:09 pm

Okay, I've been reading V8Archie's roadster build on dotnill. I really like what he did for bracing on that project. Seems like it would really help. His methods, a X-brace, and the foam would be the way to go, I'm thinking at this point. I realize that is adding a lot of extra weight, but I would want the car to remain firm.
Here's the link to the thread:
http://www.fiero.com/forum/Forum2/HTML/054448.html

And pics of where he added bracing:

Unsafe At Any Speed · Post by **Unsafe At Any Speed** » Wed Apr 18, 2007 9:11 pm

Any other ideas/thoughts?

dratts · Post by **dratts** » Thu Apr 19, 2007 9:33 am

My 355 spider had reinforcement by a nascar builder, but I think he only built it to the specs of the body manufacturer. I'm not satisfied and was also looking at Archies job. In a few places he specified 3/8" plate which I thought was way more than needed. From what I see of his engineering, he makes things bigger in order to insure no failure, rather than do calculations as to stresses. I do think that he has done the strongest reinforcement for the convertible Fiero.

Unsafe At Any Speed · Post by **Unsafe At Any Speed** » Thu Apr 19, 2007 9:46 am

Dratts, what did they do to your car?

Kohburn · Post by **Kohburn** » Thu Apr 19, 2007 11:39 am

going too thick on a reinforcement plate will increase loads in other areas and possibly lead to an unexpected failure. better to not overdo it and allow a certain amount of flexability

dratts · Post by **dratts** » Thu Apr 19, 2007 6:59 pm

Basically ran two 1 by 4 box beams laid sideways and connected the front and rear suspension. Somewhat similar to an Ifg frame that I have but without the x frame. I would like to have frame rails in the rockers and alongside the tunnel. I also suspect that closing the gas tank tunnel to make it a tube would have some benefit, but I don't know of anyone doing that.

Unsafe At Any Speed · Thu Apr 19, 2007 11:41 pm

Kohburn wrote:going too thick on a reinforcement plate will increase loads in other areas and possibly lead to an unexpected failure. better to not overdo it and allow a certain amount of flexability

What could fail? Wouldn't this, if anything, just put further pressure on other parts of the frame? If that's all that it took to break the frame, there's a problem anyway, I think. I guess added stress could be tranferred to the suspension.

Unsafe At Any Speed · Post by **Unsafe At Any Speed** » Mon Apr 23, 2007 1:34 pm

Bump for Tech.

Unsafe At Any Speed · Post by **Unsafe At Any Speed** » Wed Jul 11, 2007 5:24 pm

Any more ideas on this? I'm TDY right now, but as soon as I can I'd like to get to work on this project now that I actually am making decent money. So I want to get a pretty solid plan of attack down.

Right now I'm thinking that I will go ahead and add the usual undercar bracing and strengthen up a few of those points like Archee did on his project. Also, since I'll already have that many panels off I might as well try the foam in the frame thing. This all might be excessive, but I want to do my car right the first time.

Unsafe At Any Speed · Post by **Unsafe At Any Speed** » Fri Nov 07, 2008 3:03 pm

I'm going to bring this back from the dead. I still really want a Targa for my car. I think it would really compliment the other body mods I have done (and have planned).

That said, I *should* finally be able to get back to work on my car soon and want to get a general idea as to my plans for this project.

In addition to what's already been mentioned, would there be additional benefit to a simple roll bar? I'm thinking a hoop behind and above the seats along the edge of the interior (mainly for additional roll-over protection since I plan to run 4 points) anchored to the firewall and bars from the hoop to an anchor point in near the front wheel wells.

I'm not really sure if I'm explaining this the best. Thoughts? Or any other Targa thoughts in general?

CincinnatiFiero · Post by **CincinnatiFiero** » Fri Nov 07, 2008 5:31 pm

I thnk you should figure it out so I can copy you :afrocool:

Cletuses setup seems pretty rigid, but also freaking heavy.

fieroguru · Post by **fieroguru** » Sun Nov 16, 2008 12:02 pm

Here are some pics of the reinforcement I did for my Roadster as well as what a buddy is doing for his Roadster as well.

Mine was a "bolt on" unit that spanned from rear cradle bolts to the sway bar mount holes up up front. It bolted to the underbody of the chassis with many sheet metal screws through the floor pan. It weighed 200 lbs.

The main tubes were 2x6, the outer tubes by the rockers were 2x3 and the other tubes in the center section were 2x2. The front and rear connectors were 1x1 and all wall thicknesses were 1/8" (I think). There was also a 2x2 cross bracing welded in after this picture (with a removal tank section).

The 6 point roll bar was 1 1/4 x 3/16.

This car was very solid in bending and torsion and even over the roughest railroad tracks the cowl would not shake any.

Here is another roll bar setup from a roadster I came across on the net... no idea whos car:

Here is my buddies roadster in progress:

If I agree to it, I might be doing the reinforcements for another roadster after I get my 2nd frame rack built (sold the 1st one when I moved). It will be geared towards making the center tunnel much more of a structural memeber than it is today and having it tie to the strut towers and the front frame frails above the front suspension connections in addition to a U reinforcement between the A & B pillars